Method of preventing exhaust gas from leaking out of food waste disposer

ABSTRACT

A method of preventing exhaust gas from leaking out of a drying furnace is disclosed. In the method, the temperature of an exhaust passage and the temperature of a heater are measured, and turning on/off the heater is controlled in response to the measured temperatures. The present invention can be applied to all kinds of apparatuses having drying furnaces which are heated by heaters and thus generate the exhaust gas and can effectively prevent exhaust gas from leaking out of the apparatuses. Furthermore, the present invention can be more effectively applied to food waste disposers which heat food waste containing a large amount of water. In particular, the present invention is effective for circulation food waste disposers in which exhaust gas is condensed and re-supplied into a drying furnace as recirculation gas.

TECHNICAL FIELD

The present invention relates, in general, to methods of preventing exhaust gas from leaking out of a food waste disposer and, more particularly, to a method of preventing exhaust gas from leaking out of a food waste disposer in such a way that detecting the temperature of the exhaust gas is done to prevent the internal pressure of the food waste disposer from increasing, and temperature of an exhaust passage and the temperature of a heater are detected to prevent a drying furnace from overheating.

BACKGROUND ART

Generally, bad odors generated from food waste disposers are caused by a combination of various kinds of gases. Depending on conditions, such as the kind of food, the period over which food waste is left behind, a temperature at which food waste is treated, etc., the ingredients of exhaust gas differ. If food waste decomposes or undergoes abnormal fermentation, that is, anaerobic fermentation, the food waste discharges a large amount of exhaust gas which stinks and has toxicity which may be harmful to human beings.

Such exhaust gas which stinks is harmful to human beings, causes air and environment pollution, and is pernicious to the surroundings. Furthermore, institutional strategies have been strengthened, for example, environmental protection laws define offensive odors as air pollution, and regulation standards are provided. Hence, removal of substances which stink becomes an urgent problem that must be solved while satisfying commercial needs. Measures to solve this problem are urgently needed.

Food waste disposers which are connected to the sinks of households or are provided separately from sinks remove water from food waste through a series of processes including stirring, dehydrating, cutting and drying, thus reducing the volume of food waste, and thereby markedly the amount of food waste.

However, in the case of drying food waste disposers, when food waste is heated in a drying furnace, the amount of vapor in the drying furnace and the temperature in the drying furnace increase, thus increasing the internal pressure of the drying furnace.

If the internal pressure of the drying furnace increases excessively, gas may leak out through a weak portion of a gas passage. When this happens, offensive odors and vapor of food waste are discharged out of the food waste disposer. The offensive odors and vapor include harmful gas and anaerobes, and so are being blamed for health problems and for damaging natural environment.

To avoid these problems, the following technique merits consideration, that is, measuring the temperature of gas generated in the drying furnace or the temperature of gas drawn into the drying furnace and controlling the operation of a means for heating the drying furnace in response to the measured temperature.

However, controlling the heating means in response to only the temperature of the gas causes the problem of reducing the efficiency with which the food waste disposer treats food waste, because only the internal pressure of the drying furnace is taken into account and thus the operation of the heating means frequently stops.

In particular, in the case of circulation food waste disposers in which exhaust gas generated in the drying furnace condenses rather than is discharged out of the drying furnace and then is re-supplied into the drying furnace, there are additional variables, such as the conditions of food waste, a difference between the temperatures of the exhaust gas and a recirculation gas, etc. Therefore, a technique is required, which can both prevent exhaust gas from leaking out of the food waste disposer and satisfy the demands placed on food waste treatment efficiency.

DISCLOSURE OF INVENTION Technical Problem

Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a method of effectively preventing exhaust gas from leaking out of an apparatus, such as a food waste disposer, which includes a drying furnace that generates the exhaust gas.

Another object of the present invention is to provide a method which can control the operation of a heating means at appropriate times to solve the problem of reducing the food waste treatment efficiency of a food waste disposer which may result from the prevention of leakage of exhaust gas.

A further object of the present invention is to provide a method which can not only prevent exhaust gas from leaking out but can also prevent the drying furnace from overheating.

Solution to Problem

In order to accomplish the above objects, in an aspect, the present invention provides a method of preventing exhaust gas from leaking out of a drying furnace, including: (a) measuring a temperature of an exhaust passage through which the exhaust gas generated in the drying furnace by a heater flows; (b) turning off the heater when the temperature of the exhaust passage is a first temperature or more; and (c) measuring a temperature of the heater when the temperature of the exhaust passage is less than the first temperature, and turning off the heater when the temperature of the heater reaches a second temperature or more.

The method may further include: after (c) measuring, (d) turning on the heater again when the temperature of the exhaust passage is less than the first temperature and the temperature of the heater is less than the second temperature.

Preferably, heat exchange may be performed on the exhaust gas to form recirculation gas and the recirculation gas is re-supplied into the drying furnace through the exhaust passage, and the temperature of the exhaust passage that is measured at (a) may comprise a temperature of the exhaust passage which is measured when the recirculation gas flows through the exhaust passage. The exhaust passage may comprise an exhaust gas duct through which the exhaust gas flows, and a recirculation gas duct through which the recirculation gas flows. The temperature of the exhaust passage that is measured at (a) may comprise a temperature measured in the recirculation gas duct.

The temperature of the heater that is measured at (c) may comprise a temperature measured by a sensor disposed on the heater or by a sensor disposed adjacent to the heater.

The first temperature may range from 60° C. to 110° C. Preferably, the first temperature may range from 75° C. to 85° C. More preferably, the first temperature may be 80° C.

The second temperature may range from 100° C. to 200° C. Preferably, the second temperature may range from 140° C. to 150° C. More preferably, the second temperature may be 145° C.

Furthermore, at least either the temperature of the exhaust passage or the temperature of the heater may be measured by a temperature sensor or a temperature and humidity sensor.

The drying furnace may comprise a drying furnace of a food waste disposer, and the exhaust gas may comprise gas generated by heating food waste input into the drying furnace.

In another aspect, the present invention provides a food waste disposer, including: a drying furnace provided with a heater; a heater temperature sensor disposed on a surface of the heater or at a position adjacent to the heater; an exhaust passage through which exhaust gas generated by the heater flows; an exhaust passage temperature sensor disposed in the exhaust passage; and a control unit controlling the heater in response both to a temperature of the heater measured by the heater temperature sensor and a temperature of the exhaust passage measured by the exhaust passage temperature sensor.

The exhaust passage may comprise: an exhaust gas duct through which the exhaust gas is discharged out of the drying furnace; and a recirculation gas duct through which heat exchange is performed on the exhaust gas to form recirculation gas and the recirculation gas is re-supplied into the drying furnace. The temperature of the exhaust passage may comprise a temperature measured in the recirculation gas duct.

Advantageous Effects of Invention

The present invention can be applied to all kinds of apparatuses having drying furnaces which are heated by heaters and thus generate the exhaust gas and can effectively prevent exhaust gas from leaking out of the apparatuses.

Furthermore, the present invention can be more effectively applied to food waste disposers which heat food waste containing a large amount of water. In particular, the present invention is effective for circulation food waste disposers in which exhaust gas is condensed and re-supplied into a drying furnace as recirculation gas.

Moreover, the present invention not only measures the temperature of an exhaust passage to control the internal pressure of the drying furnace in response to the measured temperature but also measures the temperature of the exhaust passage and the temperature of a heater to prevent the drying furnace from overheating.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a food waste disposer which can prevent the leakage of exhaust gas generated by food waste, according to the present invention;

FIG. 2 is a flowchart of a method of preventing exhaust gas from leaking out of the food waste disposer according to the present invention; and

FIG. 3 is a graph showing a temperature (a) of a heater, a temperature (b) of a drying furnace measured by a furnace temperature sensor, and a temperature (c) of a recirculation gas measured in a recirculation gas duct as a function of time during which the food waste disposer is operated according to the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, a method of preventing exhaust gas from leaking out of a food waste disposer according to the present invention will be described in detail with reference to the attached drawings.

FIG. 1 is a perspective view of the food waste disposer which can prevent leakage of exhaust gas generated from food waste, according to the present invention. The food waste disposer includes a drying furnace 100, a heater 120, a heater temperature sensor 125, an exhaust gas outlet port 150, a furnace temperature sensor 200, a circulation fan 250, an exhaust passage, a buffer unit 400, a heat exchanger 500, a cooling fan 550, a recirculation gas inlet port 650, a recirculation gas temperature sensor 700 and a control unit 800. The exhaust passage includes an exhaust gas duct 300 and a recirculation gas duct 600.

The construction and operation of the food waste disposer according to the present invention will be described in more detail with reference to FIG. 1.

The drying furnace 100 receives food waste and treats it by carrying out a series of processes including stirring, dehydrating, drying and pulverizing, before high-temperature and high-humidity gas evaporated from the food waste is discharged out of the drying furnace 100 through the exhaust gas outlet port 150.

The furnace temperature sensor 200 detects the temperature in the drying furnace 100 and outputs it. In the present invention, the furnace temperature sensor 200 may comprise a temperature and humidity sensor which can sense both temperature and humidity. Furthermore, any sensing device can be used as the furnace temperature sensor 200, so long as it can sense temperature.

The circulation fan 250 receives, from the exhaust gas outlet port 150, high-temperature and high-humidity exhaust gas evaporated from food waste and circulates it.

The exhaust gas duct 300 functions to transmit the high-temperature and high-humidity exhaust gas of food waste from the circulation fan 250 to the buffer unit 400.

The buffer unit 400 receives the high-temperature and high-humidity exhaust gas of food waste from the exhaust gas duct 300, condenses it, and discharges condensation water therefrom.

The heat exchanger 500 receives from the buffer unit 400 food waste exhaust gas from which condensation water has been removed, and then cools the exhaust gas.

The recirculation gas duct 600 receives the cooled food waste exhaust gas from the heat exchanger 500 and supplies it again into the drying furnace 100 through the recirculation gas inlet port 650.

In an embodiment, the exhaust passage including the exhaust gas duct 300 and the recirculation gas duct 600 is a circulation passage. Exhaust gas may directly condense in the circulation passage, thus forming condensation water.

The recirculation gas temperature sensor 700 is mounted to the recirculation gas duct 600 or the recirculation gas inlet port 650 to measure the temperature of cooled and dried recirculation gas which is re-supplied into the drying furnace 100. The recirculation gas temperature sensor 700 may comprise a temperature and humidity sensor which can sense both temperature and humidity. Furthermore, any sensing device can be used as the recirculation gas temperature sensor 700, so long as it can sense temperature.

The heater 120 heats the drying furnace 100 in response to the control of the control unit 800 to dry food waste in the drying furnace 100.

The heater temperature sensor 125 senses the temperature temp2 of the heater 120 and outputs it. The heater temperature sensor 125 may be disposed in the heater 120 or, alternatively, it may be disposed adjacent to the heater 120, as will be explained in detail later.

The control unit 800 controls various operations of the food waste disposer. In addition, the control unit 800 controls the heater 120 in response to the temperature temp2 of the heater 120 and the temperature temp1 of the exhaust passage according to the method of the present invention. The detailed control method will be described below.

Hereinafter, the method of preventing exhaust gas from leaking out of the food waste disposer according to the present invention will be explained with reference to FIGS. 2 and 3.

The main concept of the method of the present invention is to measure the temperature temp1 of the exhaust passage and the temperature temp2 of the heater and control the On/Off status of the heater in response to the temperatures temp1 and temp2.

For example, when at least either the temperature temp1 of the exhaust passage or the temperature temp2 of the heater is a predetermined reference temperature or more, the heater is turned off to prevent exhaust gas from leaking out and prevent the elements from overheating. After the heater has been turned off, the entire temperature of the elements is reduced. When both the temperature temp1 of the exhaust passage and the temperature temp2 of the heater falls below the reference temperature, the heater is turned on again.

As stated above, the exhaust passage includes the exhaust gas duct 300 and the recirculation gas duct 600. The temperature temp1 of the exhaust passage can be measured in any one of the exhaust gas duct 300 and the recirculation gas duct 600. For the sake of explanation, although the temperature temp1 of the exhaust passage will be explained as being a temperature measured in the recirculation gas duct 600, the temperature temp1 of the exhaust passage must be interpreted as a temperature measured in the exhaust passage including the recirculation gas duct 600.

The temperature temp2 of the heater is measured to detect whether the drying furnace is overheated by the heater. Therefore, the heater temperature sensor 125 must be understood as a concept including not only a temperature sensor which is disposed in the heater or is brought into direct contact with the heater to measure the temperature of the heater, but also a temperature sensor which can measure the surrounding temperature of the heater or the temperature of a member that directly or indirectly covers the heater. Furthermore, the temperature temp2 of the heater must also be regarded as a concept including not only the temperature of the heater itself but also the temperature of the surroundings of the heater.

At step S100, when a user turns on a power button of the food waste disposer after opening an inlet door of the food waste disposer and supplying food waste thereinto, the heater 120, the circulation fan 250 and the cooling fan 550 are turned on and operated.

Then, the heater 120 heats the drying furnace 100 to dry the food waste in response to the control of the control unit 800. The heater temperature sensor 125 senses the temperature temp2 of the heater and outputs it.

As shown in FIG. 3, turning the heater 120 on and off is periodically repeated over the time that the food waste disposer is being operated. Thereby, the temperature of the drying furnace 100 repeatedly increases and falls back down. The furnace temperature sensor 200 senses the temperature of the drying furnace 100 and outputs it.

At step S110, the drying furnace 100 treats the food waste by carrying out a series of processes including stirring, dehydrating, drying and pulverizing on it. High-temperature and high-humidity exhaust gas generated during the treatment is discharged out of the drying furnace 100 through the exhaust gas outlet port 150.

At step S130, high-temperature and high-humidity exhaust gas which is discharged from the drying furnace 100 is moved to the exhaust gas duct 300 by the operation of the circulation fan 250.

At step S140, the exhaust gas reaches the heat exchanger 500 and is cooled.

During this process, condensation water forms. The condensation water enters the buffer unit 400 and then is discharged out of the food waste disposer.

Furthermore, during this process, high-temperature and high-humidity exhaust gas becomes low-temperature recirculation gas after undergoing heat exchange. The low-temperature recirculation gas is re-supplied into the drying furnace 100 through the recirculation gas duct 600, thus forming a circulation cycle, at step S150.

Meanwhile, during the series of processes, at step S160, the furnace temperature sensor 200 measures the temperature of the drying furnace in real time. At step S200, the control unit 800 receives temperature data of the drying furnace from the furnace temperature sensor 200 and determines whether the temperature of the drying furnace has reached a third temperature. Here the third temperature preferably ranges from 105° C. to 115° C. and, more preferably, it is 110° C.

When it is determined that the temperature of the drying furnace does not reach the third temperature, the temperature temp1 of the recirculation gas is measured by the recirculation gas temperature sensor 700, at step S210. When it is determined (at t3 of FIG. 3) that the temperature of the drying furnace has reached the third temperature, the algorithm for preventing the exhaust gas from leaking out of the food waste disposer of the present invention finishes.

At step S300, the control unit 800 receives data about the temperature temp1 of the recirculation gas from the recirculation gas temperature sensor 700 and determines whether the temperature temp1 has reached a first temperature. Here, the first temperature ranges from 60° C. to 110° C. and, more preferably, it ranges from 75° C. to 85° C. The inventor of the present invention found out from many tests that it is most preferable that the first temperature be 80° C.

When it is determined (at t1 of FIG. 3) that the temperature temp1 of the recirculation gas has reached the first temperature, at step 5450, the control unit 800 turns off the heater 120 while maintaining the circulation fan 250 and the cooling fan 550 in their turned-on states so that food waste exhaust gas discharged from the drying furnace 100 sufficiently circulates and is cooled. When it is determined that the temperature temp1 has not reached the first temperature, the temperature temp2 of the heater is measured to check whether the heater is overheating, at step S310.

At step S400, the control unit 800 receives the temperature temp2 of the heater from the heater temperature sensor 125 and determines whether the temperature temp2 has reached a second temperature. Here, the second temperature ranges from 100° C. to 200° C. and, more preferably, it ranges from 140° C. to 150° C. The inventor of the present invention found out from many tests that it is most preferable that the second temperature be 145° C.

When it is determined that the temperature temp2 of the heater has reached the second temperature, at step S450, the control unit 800 turns off the heater 120 while maintaining the turned-on state of the circulation fan 250 and the cooling fan 550 so that food waste exhaust gas discharged from the drying furnace 100 sufficiently circulates and is cooled. When it is determined that the temperature temp2 has not reached the second temperature, the process is returned to step S110 and repeats the succeeding steps.

At step S450, when the heater 120 is turned off while the circulation fan 250 and the cooling fan 550 are maintained in turned-on states, the temperature temp1 of the recirculation gas slowly falls, at step S460. Furthermore, the internal pressure of the drying furnace 100 can no longer increase but is reduced, at step S470.

The reason for this is that as the temperature of the drying furnace 100 falls after the heater 120 has been turned off, the amount of high-temperature and high-humidity exhaust gas evaporated from food waste is reduced, and because exhaust gas that has been cooled and dried by the circulation fan 250 and the cooling fan 550 is re-supplied into the drying furnace 100 via the recirculation gas duct 600, the temperature temp1 of the recirculation gas falls.

Thereby, the internal pressure of the drying furnace 100 can be prevented from excessively increasing. Thus, there is no probability of the exhaust gas leaking out through a weak portion of the gas passage. In addition, a bad smell and vapors generated from food waste is restrained from leaking out of the food waste disposer, thus fundamentally removing risk factors which may damage the health of the human body and the natural environment.

With regard to the point of time at which the heater that was turned off is turned back on again, it is preferable that the heater be turned on when the temperature temp1 of recirculation gas which is measured in real time is less than the first temperature and the temperature temp2 of the heater is also less than the second temperature.

In the embodiment of the present invention, although the heater is turned off when the temperature of the drying furnace becomes higher than the third temperature (in section T2 of FIG. 3), a food waste disposer according to another embodiment of the present invention may be configured in such a way that turning the heater on and off is repeated in section T2 on a cycle shorter than that of section T1 in which drying food waste is continuous.

Although the preferred embodiments of the present invention have has been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. 

1. A method of preventing exhaust gas from leaking out of a drying furnace, comprising: (a) measuring a temperature of an exhaust passage through which the exhaust gas generated in the drying furnace by a heater flows; (b) turning off the heater when the temperature of the exhaust passage is a first temperature or more; and (c) measuring a temperature of the heater when the temperature of the exhaust passage is less than the first temperature, and turning off the heater when the temperature of the heater reaches a second temperature or more.
 2. The method according to claim 1, further comprising: after (c) measuring, (d) turning on the heater again when the temperature of the exhaust passage is less than the first temperature and the temperature of the heater is less than the second temperature.
 3. The method according to claim 1, wherein heat exchange is performed on the exhaust gas to form recirculation gas and the recirculation gas is re-supplied into the drying furnace through the exhaust passage, and the temperature of the exhaust passage that is measured at (a) comprises a temperature of the exhaust passage which is measured when the recirculation gas flows through the exhaust passage.
 4. The method according to claim 3, wherein the exhaust passage comprises an exhaust gas duct through which the exhaust gas flows, and a recirculation gas duct through which the recirculation gas flows, and the temperature of the exhaust passage that is measured at (a) comprises a temperature measured in the recirculation gas duct.
 5. The method according to claim 1, wherein the temperature of the heater that is measured at (c) comprises a temperature measured by a sensor disposed on the heater or by a sensor disposed adjacent to the heater.
 6. The method according to claim 1, wherein the first temperature ranges from 60° C. to 110° C.
 7. The method according to claim 6, wherein the first temperature ranges from 75° C. to 85° C.
 8. The method according to claim 7, wherein the first temperature is 80° C.
 9. The method according to claim 1, wherein the second temperature ranges from 100° C. to 200° C.
 10. The method according to claim 9, wherein the second temperature ranges from 140° C. to 150° C.
 11. The method according to claim 10, wherein the second temperature is 145° C.
 12. The method according to claim 1, wherein at least either the temperature of the exhaust passage or the temperature of the heater is measured by a temperature sensor or a temperature and humidity sensor.
 13. The method according to claim 1, wherein the drying furnace comprises a drying furnace of a food waste disposer, and the exhaust gas comprises gas generated by heating food waste input into the drying furnace.
 14. A food waste disposer, comprising: a drying furnace provided with a heater; a heater temperature sensor disposed on a surface of the heater or at a position adjacent to the heater; an exhaust passage through which exhaust gas generated by the heater flows; an exhaust passage temperature sensor disposed in the exhaust passage; and a control unit controlling the heater in response both to a temperature of the heater measured by the heater temperature sensor and a temperature of the exhaust passage measured by the exhaust passage temperature sensor.
 15. The food waste disposer according to claim 14, wherein the exhaust passage comprises: an exhaust gas duct through which the exhaust gas is discharged out of the drying furnace; and a recirculation gas duct through which heat exchange is performed on the exhaust gas to form recirculation gas and the recirculation gas is re-supplied into the drying furnace, and the temperature of the exhaust passage comprises a temperature measured in the recirculation gas duct. 